Mutagenicity of 1,2-dichloroethane and 1,2-dibromoethane in two human lymphoblastoid cell lines.

1,2-Dichloroethane (DCE) and 1,2-dibromoethane (DBE) were tested for the ability to induce gene mutations in two human lymphoblastoid cell lines, designated AHH-1 and TK6. Both chemicals were 'direct-acting' mutagens in both cell lines. DBE was essentially equally mutagenic in TK6 cells and AHH-1 cells. In contrast, DCE was 25-fold more mutagenic in the AHH-1 cell line than in the TK6 cell line. This differential sensitivity between AHH-1 cells and TK6 cells was related to the levels of glutathione S-transferase activity in these two cell lines.